Revert "Create the CSRF token on the bounded elactic scheduler"

Reactor did not add bounded elastic until a later version.

This reverts commit c0154f2.

Author: rwinch

web/src/main/java/org/springframework/security/web/server/csrf/WebSessionServerCsrfTokenRepository.java

@@ -18,7 +18,6 @@
 import org.springframework.util.Assert;
 import org.springframework.web.server.ServerWebExchange;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Schedulers;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
@@ -49,9 +48,7 @@ public class WebSessionServerCsrfTokenRepository
 
 	@Override
 	public Mono<CsrfToken> generateToken(ServerWebExchange exchange) {
-		return Mono.just(exchange)
-			.publishOn(Schedulers.boundedElastic())
-			.fromCallable(() -> createCsrfToken());
+		return Mono.fromCallable(() -> createCsrfToken());
 	}
 
 	@Override